This sponsorship is very important for the project. Not for financial reasons, but because it gathered recognition from the company that creates much of the critical infrastructure and bot protection services.
Without this recognition, the engine could have been blocked by impassable CAPTCHAs, which for the end user would mean the project is dead at its roots.
Yes most web properties have voluntarily adopted Cf as their only protection option. Do you or I have the power to get hundreds of millions if not billions of these properties off of Cf? No, so yes they're a reality of the Web at this point, sadly. They can be no more avoided than say the tier 1 ISPs.
Without this recognition, the engine could have been blocked by impassable CAPTCHAs, which for the end user would mean the project is dead at its roots.